WO2020078553A1

WO2020078553A1 - Electrochemical system for the synthesis of aqueous oxidising agent solutions

Info

Publication number: WO2020078553A1
Application number: PCT/EP2018/078559
Authority: WO
Inventors: Vitold Bakhir
Original assignee: Blue Safety Gmbh
Priority date: 2018-10-18
Filing date: 2018-10-18
Publication date: 2020-04-23
Also published as: US11858833B2; JP7026985B2; CN112912544A; CA3117252A1; JP2022505099A; EP3867422A1; CN112912544B; EP3867422B1; EA039722B1; ES2916459T3; EA202100115A1; US20210355589A1

Abstract

The invention concerns the field of chemical technology and relates in particular to devices for the electrolysis of aqueous alkali metal chloride solutions to obtain chlorine, chlorine compounds, oxygen, ozone, and hydroperoxide compounds and can be used for disinfection in the medical, pharmaceutical, and food industry and in the purification and sterilisation of water by means of aqueous solutions of chlorine-oxygen oxidants and hydroperoxide oxidants.

Description

Electrochemical system for the synthesis of aqueous oxidizing agent solution

The invention relates to the field of chemical technology and relates in particular to devices for the electrolysis of aqueous alkali metal chloride solutions for the production of chlorine, chlorine compounds, oxygen, ozone and hydroperoxide compounds and can be used for disinfection in medicine, pharmacy and food industry as well as in cleaning and the sterilization of water by aqueous solutions of chlorine oxygen and hydroperoxide oxidants.

The solutions of chlorine oxygen and hydroperoxide compounds are obtained in the electrolysis of aqueous alkali metal chloride solutions by dissolving products of anodizing chloride solutions in water, mostly sodium chloride solutions, in the membrane or diaphragm method. Conventional processes in the electrolysis technology of aqueous sodium chloride solutions are the purification of aqueous starting sodium chloride solutions from hardening agents, heavy metals and admixtures of organic compounds, all of which occur in starting rock salt and are extremely difficult with traditional processing methods from salt intended for use, e.g. B. in the food industry to be removed. In addition to the main device, the electrolysis apparatus, various auxiliary devices are used for the electrochemical synthesis, which are referred to in their entirety as a technical electrochemical system. Most technical electrochemical systems include, in addition to the actual electrochemical reactor, which consists of a membrane or diaphragm electrolysis apparatus with an external separator tank, heat exchangers, regulators for the pressure and flow rate of liquids and gases, additional devices for producing and cleaning the saline solution of hardening agents , multivalent metal ions, organic admixtures as well as ion exchange or reverse osmosis systems for cleaning the water from hardening agents as well as collecting containers for the products of electrochemical synthesis, in particular soda acoustic and hypochlorite solutions.

A method is known for obtaining products for the electrolysis of sodium chloride solutions in a technical electrochemical system, which is described in patent RU 2 509 829 C2.

This process is carried out using a technical electrochemical system that In addition to the membrane electrolysis apparatus, it also includes a salt dissolving tank, the task of which is to integrate the processes of salt storage and the production of the actual concentrated salt solution, which is simultaneously used by hardening agents and multivalent metals by converting the soluble compounds into insoluble hydroxides by metered introduction of catholyte into the saline solution is cleaned. In this container, the salt solution is cleaned of organic admixtures by the metered introduction of hydrogen peroxide solution. The technical electrochemical system which realizes the claimed method also includes an activated carbon filter and a filter with ion exchange resin for removing the residual amounts of multivalent cations, which are arranged one after the other in the feed line for the salt solution to the electrolysis apparatus. After the ion exchange filter, the metered introduction of hydrochloric acid into the supply line for the saline solution to the electrolysis apparatus is provided in order to avoid a harmful effect of the hypercaustic saline solution on the anode coating and the unproductive electrical energy expenditure for the oxidation of the hydroxide ions and the mass transfer of monovalent sodium cations through the membrane in to reduce the cathode space.

A disadvantage of the technical solution according to patent RU 2 509 829 C2 is the need to use various additional reagents for reprocessing the ion exchange filter, for oxidizing the organic compounds in the salt solution, for correcting the pH of the salt solution that gets into the anode compartment of the electrolysis apparatus, as well as in the necessary periodic replacement of the carbon filter bed. In this regard, this electrochemical system often has to be maintained, constantly checked and its operating parameters corrected.

The device chosen as the prototype according to US Pat. No. 7,897,023 B2 is closest to the technical nature and the result to be achieved. This device represents an electrochemical system comprising a diaphragm electrolysis apparatus with a ceramic tubular ultrafiltration diaphragm, with a catholyte and anolyte circulation circuit with corresponding separating tanks for separating electrolysis gases and with heat exchanger devices for cooling the catholyte and anolyte Dosing pump with salt solution container existing device for supplying the cleaned salt solution under pressure into the anode compartment, a device for dissolving the moist gaseous products of the electrochemical anode reactions in the water stream to obtain the oxidizing agent solution, a device for overpressure stabilization in the anode compartment, a collecting container for the oxidizing agent solution and a device for the metered introduction of catholyte from the deposition container of the cathode circuit into the oxidizing agent solution to be synthesized. A disadvantage of this device is that multivalent ions, including heavy metal ions, are present in the finished product, ie in the solution of chlorine oxygen and hydroperoxide oxidants in water. These ions usually occur in drinking water or natural fresh water, which is used for the preparation of the starting salt solution and for the recovery of the oxidizing agent solution by dissolving the gaseous products of the electrochemical anode reactions in the fresh water stream, which contain microdrops of moisture with dissolved singlet oxygen, ozone and hydrogen peroxide . Multivalent metal ions, and especially heavy metal ions, are known to be catalysts for the chemical decomposition of active chlorine and active oxygen compounds - hypochlorous acid and hydrogen peroxide. For this reason, the oxidant solutions produced in this device lose their bioactivity within a few days due to the self-decomposition under the action of catalytically active ions. Another disadvantage of this technical solution is the necessary periodic cleaning of the electrode rooms of the electrochemical reactor from oxidized organic compounds of various kinds, which are contained in small amounts in the hard salt used to prepare the starting salt solution and in the water after the device for water softening with ion exchange resins can. In the period between the cleaning processes of the electrochemical reactor it is necessary to periodically change the set operating parameters of the electrochemical system by adapting them to the deteriorating operating conditions due to the formation of deposits in the electrochemical reactor. These operations require time and operator attention for all peripheral devices that are part of the unified technical electrochemical system for the synthesis of the oxidant solution: for the water softener, for the device for producing saline solution and for the regulating devices.

The object of the invention is to increase the time over which the biocidal properties of the end product, the oxidizing agent solution, are obtained by cleaning the water from hardening agents and multivalent metal diodes, and the time for the continuous or repeated short-term operation of the electrochemical system between the maintenance operations extend without having to correct its operating parameters by cleaning the salt solution from organic admixtures while completely avoiding the consumption of additional chemical reagents.

The technical result of the invention is achieved in that, in contrast to the known technical solution, when the water enters the device for mixing the fresh water stream with the gaseous oxidizing agents, a filter is arranged in front of which A supply line for the fresh water is a device for the metered introduction of the catholyte from the separating container of the cathode circuit into the water flow and the salt in the device for the supply of the salt solution into the anode compartment by means of the metered introduction of the oxidizing agent solution from the collecting container into the container of the salt dissolving device is solved, at the output of which a filter is arranged, which is connected to the input of the metering pump for supplying the salt solution under pressure into the anode compartment of the electrolysis apparatus.

1 shows the basic hydraulic circuit diagram of the electrochemical system for the synthesis of the oxidizing agent solution from alkali metal chlorides, preferably sodium chloride.

The electrochemical system includes a diaphragm electrolysis apparatus electrochemical reactor (1) with coaxially arranged electrodes - the anode (2), the cathode (3) and the diaphragm (4). The procedural scheme of the anode synthesis of the oxidizing agents consists of the anode compartment (5) of the reactor (1), the input of which is connected via the check valve (6) to the outlet of the flosh pressure metering pump (7), the input of which in turn is connected to the filter (8) connected to the container for dissolving the salt (9), in which the starting salt solution is prepared and purified. The outlet of the anode compartment (5) is connected to the separating container (10) for separating the gaseous products of the electrochemical anode reactions from the anolyte. The outlet in the lower part of the separating tank (10) is connected to the inlet of the anode compartment (5) of the electrochemical reactor (1), the anode circuit of the anolyte thereby being closed. The outlet in the upper part of the separating container (10) is connected via the check valve (11) to the device (12) for dissolving the gaseous products of the electrochemical anode reactions in fresh water. The output of the device (12) is connected to the upstream pressure regulator (13) which, when the electrochemical system is in operation, ensures that the pressure in the anode circuit of the electrochemical reactor (1) is constantly exceeded by the pressure in the cathode circuit by building up a regulated, predetermined hydraulic resistance in the oxidant solution stream . In the hydraulic line, which connects the outlet of the device (12) with the admission pressure regulator (13), there is a sensor for the conductivity of the

Oxidizing agent solution "X _s " arranged. The output of the pre-pressure regulator (13) is connected to the input of the collecting container for the oxidizing agent solution (14), which is equipped with sensors for the permissible maximum (15) and minimum (16) level of the oxidizing agent solution.

One of the outputs of the collecting container for the oxidant solution (14) is with the entrance of the container (9) for producing and cleaning the saline solution, which is lower than the collecting container of the oxidizing agent solution (14). The other outlet of the container (14) is connected to the inlet of the metering pump (17), which is intended for the supply of the oxidizing agent solution to the application, for. B. at the point of incorporation of the oxidizing agent into the water supply system to sanitize the drinking water.

The water enters the device (12) for dissolving the gaseous products of the electrochemical anode reactions via the check valve (18) and the heat exchange system of the anode circuit of the electrochemical reactor (1) from the outlet of the filter (19). In the hydraulic line, which connects the outlet of the heat exchange system of the anode circuit of the electrochemical reactor (1) and the inlet of the check valve (18), there is a sensor for the conductivity of the water "X _w ". At the inlet of the filter (19), the water which has passed through the heat exchange device (20) of the cathode circulation circuit is fed with an addition of catholyte from the separation circulation container of the catholyte (21). The catholyte is introduced into the water flow at the outlet from the heat exchange device of the cathode circulation circuit (20) by means of a metering pump (22). In the hydraulic line, which connects the outlet of the water and the inlet of the filter (19), a sensor for the conductivity of the outlet water “X” is arranged before the point of introduction of the catholyte from the separating circulation container of the catholyte (21). In addition to the heat exchange device (20) for cooling the catholyte and the separating circulation container of the catholyte (21), the cathode circuit of the catholyte comprises the cathode chamber (23) of the electrochemical reactor (1), the circulation pump (24) and the valve (25) Filling the recycle circulation tank of the catholyte (21) when the system is started up and purified water is fed in when the system is in operation. The separating circulation tank of the catholyte (21) is provided with a drain line of the catholyte, which is formed during operation of the system. The water is fed to the electrochemical system for the synthesis of the oxidizing agent solution from the pressurized water supply network via the coarse filter (pre-filter) (26), the electromagnetic valve (27) and the secondary pressure regulator (28).

The electrochemical system for synthesizing the oxidant solution works as follows.

When the electrochemical system is started up for the first time (in the absence of water and solutions in the system), the container (9) with hard salt is added in the amount required for the synthesis of the specified amount of oxidizing agent solution in a ratio of maximum consumption of 0.8 Grams of salt filled per 1 liter of oxidizing agent solution. For example, for the production of 25,000 liters of oxidizing agent solution with a concentration of active substances (chlorine oxygen and hydroperoxide compounds) of 500 mg / l, the container (9) must be filled with 20 kilograms of salt. The container (9) is filled with purified and softened water, the salt having to be completely covered with water. This is done once, when the system is started up for the first time. The connection for the water supply at the entrance of the mechanical filter (26) is connected to the pressure line for the fresh water (drinking water). The normally closed electromagnetic valve (27) is supplied with voltage by means of a separate switch. The specified volume flow of water through the system and the specified pressure in the anode circuit are set by a secondary pressure regulator (28) and a pre-pressure regulator (13), based on the display values of the pressure gauge M and the external flow meter (not shown on the drawing) .

By means of the valve (25) we fill the separating tank of the catholyte (21) with water until the water jet comes out of the drain line of the separating tank (21), then the valve is brought into a position which ensures that water enters the separating circulation tank for the Catholyte (21) is fed at a rate of 20-30 drops per minute (is determined on the basis of the speed of the drop of the drop from the drain line of the separating container for the catholyte (21)). The metering pump (7) is switched on and the anode compartment (5) of the electrochemical reactor (1) is filled with salt solution from the container (9). The end of the filling process is determined by increasing the sensor values for the

Conductivity of the oxidizing agent solution "X _s " is approximately twice that of

Values of the sensor for the conductivity of the water "X _w " determined. The control of the electrical devices of the system (pumps, power source of the electrochemical reactor) is based on the automatic block (not shown in the drawing), which with the sensors for the level of the oxidizing agent solution in the collecting container (14) and

Sensors for the conductivity of the conditioned softened water "X _w ", the

Oxidizing agent solution "X _s " and the source water "X" is connected. At a level of the oxidizing agent solution in the collecting container (14) under the measuring sensor (16) or between the measuring sensors (16) and (17) the current source of the electrochemical reactor (not shown on the drawing), the catholyte circulation pump (24), the pump (22) for the metered introduction of the catholyte into the fresh water stream and the metering pump (7) for the supply of the salt solution into the anode compartment (5) of the electrochemical reactor (1). The automatic block, which controls the electrical devices of the electrochemical system, regulates the speed for the supply of the catholyte of the metering pump (22) into the output fresh water based on the signals from the water conductivity sensors "X _w " L "by maintaining the water conductivity after the filter (19) determined by the conductivity sensor" X _w ”is to be kept at the specified value of the measuring range, which is determined by the ratio X _w = (1, 0 ... 1, 5) X '. The automatic block also ensures the regulation of the speed of the supply of the salt solution by means of the metering pump (7) into the anode compartment (5) of the electrochemical reactor (1) on the basis of the signals from the sensors for the conductivity "X _w " and "X _s " by maintaining the conductivity of the oxidizing agent solution "X _s " at the specified value of the measuring range, which is determined by the ratio X _s = (1, 5 ... 2.5) X _w .

The following reactions occur when the system is operated in the electrochemical reactor (1).

The main reaction in the electrochemical reactor (1) is the release of molecular chlorine in the anode compartment (5) and the formation of sodium hydroxide in the cathode compartment (23):

NaCI + H ₂ 0 - e -> NaOH + 0.5 H ₂ + 0.5 Cl ₂ .

At the same time, the chlorine dioxide is synthesized directly from the salt solution and from the hydrochloric acid in the anode compartment with a lower current yield, which occurs when the molecular chlorine is dissolved near the anode

forms:

2NaCI + 6H ₂ 0 - 10e -> 2CI0 ₂ + 2NaOH + 5 H ₂ ;

HCl + 2H ₂ 0 - 5e -> CI0 ₂ + 5 H \

Ozone forms in the anode compartment of the reactor through direct water decomposition and through oxidation of the released oxygen:

3H ₂ 0 - 6e 0 ₃ + 6H ^' ; 2H ₂ 0 - 4e -> 4H ^' + 0 ₂ ; = ^ 0 ₂ + H ₂ 0 - 2e -> 0 ₃ + 2 H \

The formation reaction of active ones takes place with a low current yield

Oxygen compounds:

H ₂ 0 - 2e -> 2H ^' + 0 ^' ; H ₂ 0 - e -> HO '+ H ^' ; 2H ₂ 0 - 3e -> H0 ₂ + 3H ^' .

The current efficiency for the formation of chlorine dioxide, ozone, singlet oxygen and

Hydrogen peroxide increases with a decrease in the mineral content of the aqueous sodium chloride starting solution and reaches 20-30% with a salt concentration in the starting solution Range 80 - 150 g / l with an anode density of five to seven thousand amperes per square meter (5000 - 7000 A / m ² ). Increasing the salt content in the starting solution to 250-300 g / l reduces the current efficiency of the formation reactions of chlorine dioxide, ozone, singlet oxygen and hydrogen peroxide to 1-2% with an anode density of 5000-7000 A / m ² and to 0. 1 - 0.2% with an anode density of 2000 - 3000 A / m ² .

When the gaseous product of the anodization of the sodium chloride solution is dissolved in water, there is usually a reaction which is expressed by the following equation:

Cl ₂ + H ₂ 0 «-> HOCI + HCL

It is known that hypochlorous acid, the amount of which in the solution is limited by the falling pH due to the formation of hydrochloric acid, is an elementary antimicrobial agent. The pH value can be adjusted by adding alkali lye, i.e. H. e.g. As sodium hydroxide can be changed. However, this leads to the formation of undesirable (sodium chloride) and less reactive (sodium hypochlorite) products. The sodium hypochlorite as a salt of a weak acid (hypochlorous acid) and a strong base (sodium hydroxide) has a 250 to 350 times reduced antimicrobial activity compared to hypochlorous acid.

HOCI + HCl + 2NaOH -> NaOCI + NaCI + H ₂ 0.

The formation of sodium hypochlorite can be accompanied by a simultaneous increase in the pH of the oxidizing agent solution with a simultaneous increase in the concentration of the hypochlorous acid and removal of the hardening agents and the multivalent metal ions, and the like. a. of iron can be avoided by introducing catholyte containing free hydroxyl groups into the water flow.

As is known, the catholyte has an extremely high chemical adsorption activity in hydrate formation reactions. The increased reactivity of the catholyte is explained, among other things, by the large amount of free hydroxyl groups and dissolved hydrogen contained in the catholyte.

The mutual influence of catholyte and electrolytes contained in water leads to the formation of water-insoluble compounds:

The hydroxides and the flakes formed - the particle aggregates of the hydroxides with the adsorbed molecules of organic compounds, the microcolloid particles and hydrogen bubbles and the water which has been purified and freed from multivalent metal cations and which contains low concentrations of dissolved hydrogen and free hydroxyl groups, are separated off on the filter (19) , flows into the device for dissolving the oxidizing agents (12), these cause an increase in the concentration of hypochlorous acid in the oxidizing agent solution in accordance with the following reaction: Cl ₂ + H ₂ 0 + OH- -> 2HOCI.

Depending on the amount collected in the container (14) of the electrochemical system, the oxidizing agent solution is also used, in addition to its main purpose, in small quantities as an agent for dissolving the salt in the container (9), which oxidatively decomposes the organic admixtures that originally contained in the rock salt and are difficult to remove in conventional domestic salt manufacturing processes and numerous industrial applications. The oxidized and coagulated organic foreign compounds are retained by the filter (8) at the outlet of the container (9). The dissolution of the salts by the oxidizing agent solution makes it possible to ensure the microbiological purity of the agent in the salt dissolving tank. As a result, it no longer has to be regularly waited until the end of the process of dissolving the entire filled amount of salt. Before being fed into the anode compartment of the electrochemical reactor, it is not necessary to remove the multivalent metal ions, etc. from the salt solution. a. also remove heavy metal ions. All metal cations that enter the anode compartment as part of the salt solution under the influence of the pressure drop and the electric field are removed together with the liquid filter stream into the cathode compartment via the porous UV medium of the ceramic diaphragm. In the cathode compartment, the multivalent metal cations are converted into hydroxides and removed from the system via the drain line from the deposition circulation container of the catholyte (21).

The tests with the electrochemical system were carried out in comparison with the prototype of the device, which was carried out according to US Pat. No. 7,897,023 B2 and was supplemented with an ion exchanger (water softener) and with a container for dissolving the salt and for producing a saline solution. For a more precise comparative analysis, the water from the ion exchange softener was used not only to produce the salt solution, but also to dissolve the gaseous products of the anode compartment of the electrochemical reactor. The ion exchange softener was connected to the drinking water pressure line. The The device according to the US patent was also supplemented with a collecting container for the oxidizing agent solution. Both comparable systems contained an electrochemical reactor which consisted of four electrochemical modular elements (cells) according to patent EP 0 842 122 B1. The aqueous starting salt solution contained 250 g / l sodium chloride, the hardness content in the starting solution was 0.3 MG-QKB / P (1 da corresponds to 0.3566 MG-QKB / P in the electrochemical system according to US Pat. No. 7,897,023 B2 and 4 , 5 MG-QKB / P in the tank (9) of the system according to the new technical solution The reason for the difference was the low level of hardness in water after the ion exchange softener and the significantly higher level of hardness in conventional tap drinking water which originally produced the starting salt solution in the electrochemical system according to the new technical solution. The current through the electrochemical reactor in the prototype device was 40 amperes at a voltage of 5 volts. The same values were used for the electrochemical reactor in the electrochemical system according to the new Accordingly, 52 g / h of oxidizing agents were produced in each comparison system The oxidant solution, which was produced in the prototype system at a speed of 100 l / h, had an oxidant concentration of 500 mg / l, a pH of 2.8 and a total mineral content of 0.86 g / l. The hardness-forming agent content in the oxidizing agent solution was 0.2 MG-QKB / P. With a metered introduction of the catholyte, which is formed during the synthesis of the oxidizing agent solution, the pH value of the solution at the outlet increased to 6.0, while the mineral content of the solution was increased to 1.5 g / l. The oxidant solution, which is produced at a rate of 100 l / h in the device according to the new technical solution, had a pH of 3.0 at an oxidant concentration of 500 mg / l and a total mineral content of 0.66 g / l . With the metered introduction of catholyte into the initial water, the pH value of the oxidizing agent solution increased while the mineral content increased to 0.82 g / l. The hardness of the oxidizing agent solution was in the range of 0.8 MG-QKB / P, but decreased to 0.6 MG-QKB / P in the course of 2 hours of operation. The evaluation of the results of these investigations shows that the introduction of catholyte in front of the filter (19) significantly reduces the hardness of the water for dissolving the gaseous products of the anodization of the sodium chloride solution and that the introduction of the oxidizing agent solution with a reduced content of hardening agents in the container (9 ) for the production of the salt solution, the content of hardness in the oxidizing agent solution is significantly reduced.

Both systems ran continuously for 10 hours a day for 10 days. Samples of the oxidant solutions were taken twice: at the end of the second day of operating comparable electrochemical systems (20 hours of operation) and after 10 days (100 hours of operation). The solution from the prototype system showed after twenty hours of operation Systems the following values: pH 6.4; Oxidant concentration 480 mg / l; Mineral content 1.4 g / l. After ten days, the oxidant concentration in the sample taken (amount of the solution 1 liter) decreased to 460 mg / l. The hardness content in the oxidant solution of the prototype was 0.9 MG-QKB / P, ie a deterioration in the functioning of the ion exchange filter was observed. The solution from the system according to the new technical solution had the following values after 20 hours of operation of the system: pH 5.9; Oxidizer concentration 510 mg / l; Total mineral content 0.83 g / l. After 10 days, the oxidant concentration in the sample (solution sample) taken was unchanged. The hardness content in the oxidant solution of the prototype was 0.6 MG-QKB / P, ie the introduction of catholyte into the starting water in front of the filter made it possible to purify the water from hardness builders. As a result, the oxidizing agents remained in the solution for longer.

The solution from the prototype system showed the following values after one hundred hours of operation of the system: pH 6.3; Oxidant concentration 470 mg / l; Total mineral content 1.4 g / l. After 10 days, the oxidant concentration in the sample taken (amount of the solution 1 liter) decreased to 440 mg / l. The hardness level in the prototype's oxidant solution was 3.8 MG-QKB / P, which is obviously related to the significant deterioration in the function of the ion exchange filter. The solution from the system according to the new technical solution had the following values after one hundred hours of operation: Values: pH 5.9; Oxidizing agent concentration 500 mg / l; Total mineral content 0.83 g / l. After 10 days of operation, the oxidant concentration in the sample taken (solution sample) was unchanged. The content of hardening agents in the oxidizing agent solution from the system according to the new technical solution was 0.6 MG-QKB / P, ie the introduction of catholyte into the starting water before the filter made it possible to purify the water effectively from hardening agents over a long period of time . This kept the oxidizing agents in the solution longer. Examination of the containers for the solution of the salt and the production of the salt solution showed a biofilm of microorganisms in the container of the prototype system. The biofilm was completely missing in the container (9) of the system according to the new technical solution. This fact is extremely important, since the organic substances that form during the operation of the biofilm, when oxidized in the anode compartment of the electrochemical reactor, are able to cause the electrolytic decomposition of the sodium chloride by the formation of impurities on the electrodes and on which are difficult to remove To influence the diaphragm (membrane) negatively. Reference numerals

1 reactor

2 anode

3 cathode

4 diaphragm

5 anode compartment

6 check valve

7 High pressure metering pump

8 filters

9 salt

10 separation tanks

1 1 check valve

12 device

13 pre-pressure regulator

14 Oxidizer solution

15 maximum level

16 minimum levels

17 dosing pump

18 check valve

19 Filter input

20 heat exchange device

21 catholyte

22 dosing pump

23 cathode compartment

24 circulation pump

25 valve

26 coarse filter (pre-filter)

27 electromagnetic valve

28 pressure regulator

Claims

Claim

Electrochemical system for the synthesis of an oxidizing agent solution from water and a sodium chloride solution, which comprises a diaphragm electrolysis apparatus (4) with a tubular ceramic ultrafiltration diaphragm (4), a circulation circuit of the catholyte and anolyte, with corresponding separating containers (10, 21) for separating the electrolysis gases and with Heat exchanger devices (20) for cooling the catholyte and anolyte, a device for supplying aqueous salt solution into an anode space (5) of the diaphragm electrolysis apparatus (4) under pressure, which comes from a metering pump (7) with a container (9) for dissolving of the salt, there is a device for dissolving moist gaseous products of the electrochemical anode reactions in the fresh water stream to obtain an oxidizing agent solution, a device for stabilizing the excess pressure in the anode compartment (5), a collecting container (14) for the oxidizing agent solution and a device for the metered addition guidance of the catholyte from the separating container (21) of the cathode circuit into the oxidizing agent solution to be synthesized, characterized in that

A filter (19) is arranged in a feed line for the fresh water to the device for dissolving moist gaseous products of the electrochemical anode reactions, in front of which a device for the metered introduction of catholyte from the separating container (21) of the cathode circuit into the water flow in the feed line for the fresh water , which flows to the filter (19), is mounted, the dissolving of the salt in the container (9) of the device for supplying aqueous salt solution into the anode compartment (5) in the oxidant solution by means of the device for metered supply of the oxidant solution from the Collecting container (14) for the oxidizing agent solution into the salt dissolving container (9) takes place, at the output of which a filter (8) is arranged, which with the input of the metering pump (7) for supplying the salt solution under pressure into the anode compartment (5) of the electrolysis apparatus connected is.